Pulling record based on several conditions in different tables

This one is keeping me up at night.  I am trying to create an automation (or import, or really whatever works) based on several conditions that pertain to different tables.  For starters, I attached a crude .pdf of the relationships (the Triangle is the "many" side). 



So I would like to add a new "attendance" for a contacts, only if the following are met:
1) The "membership" matched the meeting (i.e. - tech committee, Board of Managers)
2) The membership is marked as "active" or the membership start date is before the meeting date.

I would like to automate this to run either 1 week before the meeting (as memberships change) or after we click the meeting as "live"

Thinking there has to be a membership to meeting relationship inserted somewhere, but not sure if I am missing something else?

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Erik Pye
Affirmant Health Partners
-Learner -Includer -Developer -Positivity -Belief
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